JSFiddle - React, Tailwind, and code Playground

HTML

<div id="1foo"></div>

<button onclick="alert($('#foo').length);">
    How many '#foo's are there?
</button>

JavaScript

var winId = 1;

$.fn.extend({
    initCore:   $.fn.init,
    init: function (selector, context, rootjQuery) {
        selector = selector.replace('#', '#' + winId);
        return $.fn.initCore(selector, context, rootjQuery);
    }
});

$.fn.init.prototype = $.fn;